A mixture of pulp and superabsorbent polymer is frequently used for the absorbent body of absorbent products such as disposable diapers, incontinence pads, incontinence liners, sanitary napkins or panty liners. Studies have been conducted on methods for recovering and reclaiming superabsorbent polymers from used absorbent products and restoring their moisture absorbency so that they can be reused.
For example, Patent Document 1 discloses a method for restoring the moisture absorbency of a superabsorbent polymer contained in a used absorbent product by adding a transition metal salt only or a mixture of a transition metal salt, an alkali metal salt or an alkaline earth metal salt to a gelled mixture of a pulp component and a superabsorbent polymer, removing the moisture contained in the superabsorbent polymer, shrinking and solidifying the superabsorbent polymer together with coloring the superabsorbent polymer with a transition metal salt, followed by respectively separating and recovering the pulp component and superabsorbent polymer, recovering the transition metal salt, alkali metal salt or alkaline earth metal salt used in separation from the separated superabsorbent polymer by acid treatment, and treating the superabsorbent polymer with base following acid treatment.